* {
    margin: 0;
    padding: 0;
    list-style: none;
    text-decoration: none;
    box-sizing: border-box;
}
.top {
    width: 100vw;
    height: 180px;
    background: #fff;
    display: flex;
    padding: 0 20px;
    position: relative;
    overflow: hidden;
}
.top-banner{
    position: absolute;
    top: 0;
    left: 0; 
    width: 100%;
    height: 100%;
    object-fit: cover; /* 保持图片比例，避免拉伸变形 */
    z-index: 0;
}
.topleft,
.search-container,
.bilibili-logo,
.topright {
    position: relative;
    z-index: 1;
}
.topleft {
    width: auto;
    height: 60px;
    display: flex;
    align-items: center;
}

.topleft li:first-child { 
    display: flex;
    align-items: center;
    gap: 20px;
}
.topleft .icon-bilibili-fill {
    font-size: 35px;
    color: #fff;
}
.topleft li {
    margin-right: 20px;
}
.topleft li a {
    color: #fff;
}
.search-container {
    display: flex;
    margin: 10px 20px 0 200px;
    opacity: 0.6;
}
.topsearch {
    width: 450px;
    height: 40px;
    border-radius: 10px;
    border: 1px solid #ccc;
    padding: 10px;
}
.search {
    width: 50px;
    height: 40px;
    background: #fff;
    border-radius: 10px;
    border: 1px solid #ccc;
    cursor: pointer;
    margin-left: 5px;
}
.bilibili-logo {
    width: auto;
    top:-10px;
    left: 20px;
}
.bilibili-logo img {
    width: 180px;
    height: auto;
}

.topright {
    width: auto;
    height: 60px;
    display: flex;
    margin-top: 10px;
    margin-left: auto;
    align-items: center;
}
.topright li {
    margin-right: 15px;
    display: block;
    text-align: center;
    width: 60px;
}
.topright li a {
    color: #fff;
    display: flex;
    flex-direction: column;
    align-items: center;
    font-size: 17px;
    font-weight: 400;
    gap:2px;
}
.topright .iconfont {
    font-size: 24px; 
    color: #fff;
}

.main {
    width: 100%;
    max-width: 2200px;
    margin: 0 auto;
}
.menu {
    width: 100%;
    height: 120px;
    background: #fff;
    margin-top: 30px;
    position: relative;
    display: flex;
    align-items: center;
}
.menuleft {
    display: flex;
    width: 190px;
    height: 120px;
}
.menuleft-ul {
    display: flex;
    width: 100%;
    text-align: center;
    justify-content:space-around;
    margin-left:40px ;
}
.menuleft-ul li {
    margin-top: 30px;
    width: 66px;
    cursor: pointer;
}
.menuleft-ul li p {
    color: black;
    font-size: 20px;
}
.menuleft-ul li a {
    display: block;
    text-decoration: none;
}

.menuleft-ul .icon-dongtai1{
    line-height: 50px;
    color: white;
    font-size: 37px;
}
.menuleft-ul .icon-remen{
    line-height: 50px;
    color: white;
    font-size: 28px;
}
.circle {
    width: 50px;
    height: 50px;
    text-align: center;
    border-radius: 100%;
    margin: 0 auto 4px;
}
.menucenter {
    width: 1700px;
    height: 100px;
    margin-left: 10px;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    padding: 0 10px;
    position: relative;
}
.menucenter li {
    width: 110px;
    height: 50px;
    line-height: 46px;
    background: #f6f7f8;
    margin: 8px;
    border-radius: 5px;
    transition: 0.3s;
    cursor: pointer;
    text-align: center;
}
.menucenter li:hover {
    background-color: #ccc;
}
.menucenter .more {
    position: relative;
}

.line {
    display: block;
    width: 1px;
    height:90px;
    margin: 10px;
    background-color: #ccc;
}

.menuright {
    width: 490px;
    height: 120px;
    display: flex;
    align-items: center;
}
.menuright-ul {
    display: flex;
    flex-wrap: wrap;
    width: 400px;
    height:90px;
    margin-top: 30px;
    justify-content: space-between;
}
.menuright-ul li {
    width: 33%;
    text-align: center;
}
.menuright-ul a {
    line-height: 34px;
    font-size: 19px;
    color: black;
    display: block;
}
.menuright-ul a:hover {
    color: #17a9da;
    text-decoration: none;
}
.menuright-ul .iconfont {
    color: #61666d;
    font-size: 21px;
    margin-right: 1px;
}

.center {
    width: 100%;
    height: auto; 
    margin-top: 60px;
    margin-left: 50px;
    display: flex;
    align-items: flex-start;
}

.centerleft {
    position: relative;
    width: 900px;
    height: 550px;
    margin-top: 10px;
    border-radius: 7px;
    overflow: hidden;
}
.box-img {
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    opacity: 0;
    transition: 0.5s;
    z-index: 0;
}
.box-img img {
    width: 100%;
    height: 100%;
    object-fit: fill;
}
.box-img.active {
    opacity: 1; 
    z-index: 1;
}
.box-left {
    position: absolute;
    width: 35px;
    height: 70px;
    color: #ccc;
    top: 50%;
    transform: translateY(-50%);
    border-radius: 5px;
    text-align: center;
    line-height: 70px;
    font-size: 37px;
    cursor: pointer;
    z-index: 10; 
    left: 0px;
}
.box-left:hover {
    background-color: #00000050;
    color: #fff;
}
.box-right {
    position: absolute;
    width: 35px;
    height: 70px;
    color: #ccc;
    top: 50%;
    transform: translateY(-50%); 
    border-radius: 5px;
    text-align: center;
    line-height: 70px;
    font-size: 37px;
    cursor: pointer; 
    z-index: 10; 
    right: 0px;
}
.box-right:hover {
    background-color: #00000050;
    color: #fff;
}
.box-choses {
    position: absolute;
    bottom: 20px;
    left: 20px;
    transform: none;
    z-index: 20;
}
.box-choses > ul {
    padding: 0;
    margin: 0;
    list-style: none;
    display: flex;
}
.box-choses li {
    width: 10px;
    height: 10px;
    border-radius: 100%;
    background-color: #ccc;
    margin-right: 8px;
    cursor: pointer;
}
.box-choses li:hover,
.box-choses li.active {
    background-color: #fff;
    transform: scale(1.2); 
}
.box-view {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 80px;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.9), rgba(0, 0, 0, 0));
    z-index: 15;
    display: flex;
    align-items: flex-end;
    padding: 15px 20px;
}
.box-title {
    color: #fff;
    font-size: 20px;
    font-weight: 500;
    line-height: 1.2;
    margin: 0 0 5px auto;
    white-space: nowrap;
    overflow: hidden;
    max-width: 70%;
    text-overflow: ellipsis;
}
.submenu {
    list-style: none;
    margin: 0;
    padding: 0;
}
.submenu li {
    width: 100%;
    float: none;
    margin: 0;
    padding: 8px 15px;
    border-bottom: 1px solid #eee;
    background: #fff;
}
.submenu li:last-child {
    border-bottom: none;
}
.submenu li:hover {
    background-color: #f5f5f5;
}
.dropdown {
    display: none;/*默认隐藏*/
    position: absolute;
    top: 50px;
    left: 0;
    background: #fff;
    border: 1px solid #ccc;
    border-radius: 4px;
    z-index: 10;
    width: 200px;
    box-shadow: 0 2px 3px rgba(0, 0, 0, 0.3);
}

.center-ul {
    display: flex;
    flex: 1;
    flex-wrap: wrap;
    align-content: flex-start;
    padding: 10px 30px;
    gap: 30px; 
}
.center-ul .video-item {
    width: 370px;
    height: 310px;
    border-radius: 6px;
    background: #fff;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    text-decoration: none;
}
.center-ul .video-item img {
    width: 100%;
    height: auto;
    display: block;
}
.center-ul .video-info {
    padding: 8px;
}
.center-ul .video-title {
    font-size: 19px;
    color: #000;
    margin-bottom: 4px;
    line-height: 1.2;
}
.center-ul .video-up{
    font-size: 18px;
    color: #666;
    margin: 0;
    line-height: 1.2;
}
.center-ul .video-title:hover,
.center-ul .video-up:hover {
    color: #17a9da; 
}
.video-up-container{
    display: flex;
    align-items: center;
    gap:4px;
}
.video-up-container .iconfont{
    font-size: 18px;
    color: #666;
}
.video-img-container{ 
    position: relative;
    width:100%;
    height:auto;
}
.video-img-container img {
    width: 100%;
    height: 100%;
    display: block;
}
.video-data {
    position: absolute;
    bottom: 8px;
    left: 8px;
    z-index: 5; 
    display: flex;
    gap: 12px; 
    color: #fff;
    font-size: 14px;
}
.video-time{
    position: absolute;
    bottom:8px;
    right:8px;
    z-index: 5;
    display: flex;
    color: #fff;
    font-size: 16px;
}
.video-view {
    position: absolute;
    bottom: 0;
    left: 0;
    z-index: 4; 
    height: 40px; 
    width: 100%;
    /* 垂直渐变 */
    background: linear-gradient(to top, rgba(0, 0, 0, 0.9), rgba(0, 0, 0, 0));
}
.video-data .play-count,
.video-data .danmu-count {
    display: flex;
    align-items: center;
    gap: 4px; 
}

.main-ul {
    width: 100%;
    background: #fff;
    display: flex;
    flex-wrap: wrap;
    padding: 10px 50px;
    gap: 15px; 
}

.main-ul .video-item {
    width: calc((100% - 60px) / 5); /* 每个间距15px */
    height: auto;
    border-radius: 6px;
    background: #fff;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    text-decoration: none;
    margin-top: 40px;
}
.main-ul .video-item img {
    width: 100%;
    height: auto;
    display: block;
}

.main-ul .video-info {
    padding: 8px;
}
.main-ul .video-title {
    font-size: 19px;
    color: #000;
    margin: 0 0 4px 0;
    line-height: 1.2;
    overflow: hidden;
}
.main-ul .video-up{
    font-size: 18px;
    color: #666;
    margin: 0;
    line-height: 1.2;
}
.main-ul .video-title:hover,
.main-ul .video-up:hover{
    color: #17a9da; 
}
